With the rapid development of mobile communications and terminal technologies, a mobile terminal is increasingly widely applied. As the mobile terminal develops rapidly, some drawbacks occur in some applications. For example, if a user needs to make a voice call when driving a car, security of the user is affected. To resolve this problem, an increasingly large quantity of vehicles are equipped with an in-vehicle device, such as in-vehicle Bluetooth.
In the prior art, when a user carries a mobile terminal into a car, based on pre-configured information, the mobile terminal may be connected to the car by using in-vehicle Bluetooth; when the mobile terminal receives a voice call and establishes a voice call, voice information may be transmitted to an in-vehicle device and broadcast by using a voice-output device (for example, a speaker or a sound) of the car, and a voice-input device (for example, a microphone) of the car may also receive the voice information of the user and transmit the voice information to the mobile terminal by using the in-vehicle device, so as to implement the voice call. Because an environment of a same car may change, for example, the car is usually taken by a family member, according to the pre-configured information, it is more convenient to complete a voice call by using an voice input/output device of the car; however, if the car is taken by a colleague or a neighbor sometime, completing a voice call by using the voice input/output device of the car may cause leakage of user privacy and further reduce a user experience effect.